1. Field of the Invention
The present invention relates generally to ergonomic support systems for receiving and supporting the forearm and/or wrist of a person engaged in an activity on a supporting surface. It may apply to the field of computer accessories and peripheral equipment for use by computer operators and, more particularly, to an ergonomic support system for receiving and supporting the forearm and/or wrist of a person operating an input-output device for a computer such as a keyboard or a mouse.
2. Description of the Prior Art
Numerous appliances are known which are pertinent to the invention at hand. One early instance is presented in U.S. Pat. No. 3,300,250 issued Jan. 24, 1967 to Dollgener et al. which discloses a cushioned arm rest for individuals whose occupations require a continuous use of their hands along the depending edge of work tables, benches, desks and the like.
U.S. Pat. No. 5,170,971 issued Dec. 15, 1992 to Schaeffer et al. discloses a wrist supporter made of polyurethane foam having an L-shape cross section which is adapted for installation along an edge of a work surface.
U.S. Pat. No. 5,195,705 issued Mar. 23, 1993 to Kline et al. discloses a microscope stand and armrest system for placement on a conventional desktop. Height adjustment and leveling feet are provided at each corner of a base plate and a top surface is hinged to the base plate for receiving a microscope and for tilting the microscope rearward toward the user to a position that allows the user to look directly forward when operating the microscope. Left and right sloping armrests which may be of polyurethane foam material are provided for placement on the desktop at each side of the microscope stand to support the user's forearms in natural positions while operating the microscope.
U.S. Pat. No. 5,342,005 issued Aug. 30, 1994 to Szmanda et al. discloses a forearm support apparatus for a keyboard operator which utilizes first and second forearm support units, each including a relatively firm base member having a tapered wall and a flat bottom wall. A complementing upper member has a similar taper and is secured to upper wall and an inverse orientation to raise the tapered wall to a top surface. The top member is formed of a highly resilient compressible material to receive the forearm which depresses the material and supports the forearm. The support units are mounted in laterally spaced relation with the tapered upper walls extending inwardly and downwardly toward each other such that the forearms are biased inwardly toward each other to restrict outward displacement. The members are formed symmetrically about a transverse plane generally parallel to the keyboard.
U.S. Pat. No. 5,492,298 issued Feb. 20, 1996 to Walker discloses an inclined mouse pad configured as a wedge, preferably molded of dense neoprene or the like, and equipped with working and decorative surfaces. When not in use, the working surface can be oriented downwardly against a table to expose the non-working surfaces to view. This protects the working surface from dust and damage from dropped objects and spills. The inclined mouse pad provides a gravity gradient in one direction, preferably the "Y" direction to give normal physiological feed back on the position of the mouse on the pad. Other advantages include ergonomic compatibility, elevation of the arm, and better control since the user pushes upward and pulls the mouse downward.
U.S. Pat. No. 5,597,218 issued Jan. 28, 1997 to Lechman discloses a wedge-like structure which is interposable between an object and its supporting substrate surface and whose thickness is adjustable for purposes of adjusting the tilt angle of the object relative to the substrate surface. The structure is comprised of a stack of generally flattened component members wherein a layer of a releasable adhesive composition is located between and bonded to adjacent component members that can have various configurations and be of a variety of compositions including rigid organic polymer foam. The wedgelike structure is said to be particularly well adapted for incorporation into a monitor support assembly that is located under a transparent window in the top portion of a work station so that the monitor tilt angle is adjustable relative to the assembly by the wedge-like structure.
More recently, in the aforementioned U.S. application Ser. No. 08/909,835, applicant herein disclosed a unique ergonomic support pad construction for supporting the forearm and wrist of a person operating a computer's input-output device. It was explained that the support pad may comprise bottom, middle, and top layers of open celled polyurethane foam material of substantially uniform thickness, preferably of the type which softens on contact with a warm surface thereby providing uniform pressure distribution and firm, yet fluid, support. The bottom layer has a bottom surface for resting on a supporting surface and the top layer has a top surface for engageably receiving the forearm and wrist of the person. Each layer exhibits different indentation force deflections, the bottom layer being firmest and the top layer being most supple. The support pad is approximately one to two inches thick, preferably four sided, and may be round or oval or of other shapes as viewed in plan. When multi-sided, it may have biased corner surfaces joining adjoining pairs of longitudinal and lateral edge surfaces. Longitudinal and lateral edge surfaces of the top layer are substantially perpendicular to the top surface and longitudinal and lateral edge surfaces of the middle and bottom layers are respectively uniformly angularly disposed with respect to the bottom surface, the bottom surface area being smaller than the top surface area. The combined thicknesses of said bottom and middle layers may be approximately equal to the thickness of the top layer. The support pad may have only two layers or more than three layers and may also be of one or more layers with each layer exhibiting a continuous gradient of values of indentation force deflections. That disclosure further explained that in a typical application, the foam may be graded so that the bottom layer exhibits an indentation force deflection, as measured by ASTM D3574 Test B1, which is in the approximate range of 488 lbf @10.degree. C., 27 lbf @21.degree. C. and 9 lbf @38.degree. C., so that the middle layer exhibits an indentation force deflection in the approximate range of 315 lbf @10.degree. C., 10 lbf @21.degree. C. and 7 lbf @38.degree. C., and so that the top layer exhibits an indentation force deflection in the approximate range of 34 lbf @10.degree. C., 4 lbf @21.degree. C. and 3 lbf @38.degree. C.
A suitable material for purposes of that invention, and continuing for the present invention, is a product manufactured under the name of CONFOR.TM. Ergonomic Urethane Foams by E.cndot.A.cndot.R Specialty Composites Division Cabot Safety Corporation of Indianapolis, Ind. The indentation force deflection gradient can be applied to a range of products for light, medium and heavy weight users. A general shape of the support pad is square, but it may be made to other various shapes to accommodate designers. The pad is preferably flat on the top surface, but it could also be sculpted.
It was with knowledge of the foregoing disclosures representative of the state of the art that the present invention was conceived and has now been reduced to practice. Indeed, the intent of the present disclosure is to more intently focus on an inventive concept first presented in the applicant's co-pending application, aforesaid, that " . . . the pad may have a continuous . . . indentation force deflection gradient from top to bottom". This gradient may be zero and this concept will be expounded upon below.